Wire coil forming means



G- C. BURD ET AL WIRE COIL FORMING MEANS Filed April 18, 1931 Patented Dec. 27, 1932 n w we; aw

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PATEhf'E GORMAN C. BURD AND OTTO BRATZ, OF ADRIAN, MICHIGAN, ASSIGNORS T0 AIEiIERICAN CABLE COMPANY, INC., A CORPORATION OF DELAWARE WIRE COIL FORMING MEANS Application filed April 18, 1931. Serial No. 531,130.

This invention relates to means for forming coiled wire structuresand has for its particular object the provision of means for deforming a' cylindrical coiled spring structure to impart to at least a portion thereof a contour of progressively diminishing radius.

Another object of the invention is topro- \ide for the above purpose an assembly of dies respectively having internal arcuate forming surfaces provided with arcuate grooves so disposed as to constitute a substantially continuous groove of progressively diminishing radius when said dies are assembled in cooperative position.

Still another object of the invention is to provide such dies, having the forming surface characteristics already described, and further characterized by having a. continuation of said forming surfaces adapted to impart a substantially cylindrical contour to another portion of the coiled structure in continuation of the portion thereof deformed with a progressively diminishing radius.

Another object of the invention is to provide forming dies of the above type which are adapted to be used in a rotary swedging machine of the type which operates upon the work in a succession of high velocity impacts applied progressively around the periphery of the work.

The above. and other, features of the invention, are illustrated and described fully in the accompanying drawing and specification and are pointed out in the claims.

In the drawing.

Fig. 1 is a view in vertical section of a pair of dies in the construction of which the invention has been embodied.

Fig. 2 is a view in front elevation of said dies.

Fig. 3 is a View in side elevation of a helically coiled spring which has been deformed by application thereto of the dies shown in Figs. 1 and 2.

Fig. 4 is a view similar to Fig. 3 of a modified form of structure deformed by the means shown in Figs. 1 and 2. a

Fig. is a view similar to Fig. 1 showing dies having forming surfaces of modified contour.

Fig. 6 is a view similar to Fig. 1 showing dies having forming surfaces of still another contour.

Fig. '4' shows the product formed by the dies of Fig. 6.

In a now preferred embodiment of the invention selected for illustration and description, the parts designated by the reference numerals 1 and 2 respectively are dies, of suitable material and dimensions. and which, in accordance with the invention. are provided with forming surfaces 3 and 4 of gen erally arcuate form and having arcuatc grooves 5 and 6, so disposed as to constitute a substantially continuous groove of progressively diminishing radius when said dies are assembled in cooperative position, as illustrated in Figs. 1 and 2.

In the instance illustrated, the grooved forming surfaces are adapted to produce a tapering spiral upon a helically coiled spring. such as that shown in Fig. 3 and designated generally by the reference character 7, the coiled spring shown being of initially cylindrical contour. although a coiled spring structure of any suitable contour may be operated upon.

In carrying the invention into effect an end of the coiled spring structure 7 is introduced into the mouth of the dies, which is of suitable diameter to receive the same,and relative rotation between the spring structure and the dies is caused in any suitable manner, as for example by rotating the spring structure 7 relatively to the dies or by means of a rotary swedging machine of any conventional or suitable type which is adapted to rotate the dies and at the same time cause a reciprocating motion of the dies 1 and 2 toward and from each other to impart a series of rapid velocity impacts to the periphery of the spring structure 7. The spring 7 is fed forward between the dies by any suitable, means. and this operation r sults in deforming the forward end of the spring to impart thereto a spiral contour of progressively diminishing radius as indicated at 8 in Fig. 3.

in the inst-awe illustrated. the dies are shown as having a continuation of t-h of the forming surfaces as shown at 9 and 10, these continuations being adapted to produce a cylindrical contour upon a portion 11 of the coiled spring extending beyond that on which the tapered portion has been produced. as already described.

It the spring be worked upon only to an extent corresponding to the tapered portions of the working surfaces, the product will be of the shape shown in Fig. 3, with a taper 8 at the end of the spring, but if the action of the dies be continued as the spring structure is fed forward, the latter will be provided with a cylindrical extension beyond the tapered portion as shown in Fig. 4 at 11.

In the instance illustrated in Figs. 1 and 3, the coiled spring ,7 has closely wound convolutions. and the spiral grooves 5 and 6 are adapted to carry out the deforming step while preserving the close arrangement of the coils, but it will be understood that such dies can operate upon a coiled spring having its component coils spaced apart, the dies acting to produce a tapered portion with closely arranged coils, or dies may be provided. as illustrated in Fig. 5, at 1 5 and 16,

having forming surfaces with grooves adapted to produce a tapered portion having its convolutions spaced apart when the dies are applied. as already described. to work the periphery of a coiled spring having closely arranged coils in its original condition.

So also. while, in the instance illustrated, the dies are adapted to produce the evenly tapered contour illustrated at 8 in Fig. 3, it will be understood that by suitable conformation of the forming surfaces, for example as shown at 25 and 26 in Fig. 6, a contour of any desired and suitable form embodying the feature of a progressively dim nishing radius, may be produced, such as the bee-hive contour shown at 18 in Fig. 7.

It will be clear from the above description that the provision of dies with forming surfaces having arcuate grooves of progressively diminishing radius and acting upon the original coiled structure in the substantially continuous rotative manner described, with a series of high velocity impacts, makes it possible to produce a final structure of notable regularity and in Which the constituent material has been improved in resilience and other desirable characteristics by the hammer tempering resulting from the operation of deforming in the manner described; also that the means described lend themselves favorably to rapid and inexpensive production of such coiled springs in large quantities.

Having thus described the illustrated embodiment of our invention and having in mind that variations and modifications of the same may be made, we define the scope of the invention by the following claims.

We claim:

1. Forming means 'for deforming a helically coiled wire structure to impart thereto a contour of progressively varying radius, said means comprlsing a plurality of dies respectively having internal arcuate forming surfaces provided with arcuategrooves so disposed as to constitute'a substantially con tinuous helical groove of progressively varying radius when said dies are assembled in co-operative position.

2. Forming means for deforming a helically coiled wire spring structure to impart thereto a contour of progressively diminishing radius, said means comprising a plurality of dies respectively having internal arcuate forming surfaces provided with arcuate grooves so disposed as to constitute a substantially continuous helical groove of progressively diminishing radius when said dies are assembled in co-operative position.

Forming means for deforming a helically coiled wire structure to impart to a portion thereof a contour of progressively varying radius, said means comprising a plurality of dies respectively having internal arcuate forming surfaces provided with arcuate grooves so disposed as to constitute a substantially continuous helical groove of progressively varying radius when said dies are assembled in co-operative position, said dies having a continuation of said forming surfaces provided with a helical groove of constant radius.

4. Forming means for deforming a helically coiled wire structure to impart thereto a contour of progressively varying radius, said means comprising a plurality of dies respectively having internal arcuate forming surfaces provided with arcuate grooves so disposed as to constitute a substantially con tinuous helical groove of progressively varying radius when said dies are assembled in co-operative position, said dies being adapted to be applied to the periphery of said coiled spring in a multiplicity of high velocity impacts. 7

5. Forming means for deforming a helically coiled wire structure to impart thereto a contour of progressively varying radius, said means comprising a plurality of dies respectively having internal arcuate forming surfaces provided with arcuate grooves so disposed as to constitute a substantially continuous groove of progressively varying radius when said dies are assembled in co-op erative position. said grooves having portions so spaced as to cause separation of the helical convolutions deformed thereby.

In testimony whereof, we have signed this specification.

GORMAN C. BURD. OTTO BRATZ. 

